1. Field of the Invention
The present invention relates to a semiconductor test apparatus.
2. Description of the Related Art
A semiconductor test apparatus is used for determining whether a semiconductor integrated circuit operates in the same way as designed. The semiconductor test apparatus supplies a predetermined test pattern to a semiconductor integrated circuit (hereinafter, simply referred to as a DUT: Device Under Test) to be tested, so that the DUT executes processing based on the test pattern. As a result, if the processing by the DUT is normally completed, the DUT is determined as pass.
When the DUT is a memory or the like, resistance characteristics thereof against power supply voltages are often checked by changing a power supply voltage to be supplied to the DUT. In the test apparatus disclosed in Patent Document 1, the resistance characteristics of the DUT have been checked by changing a power supply voltage at every time when a series of test patterns are supplied to the DUT.    [Patent Document 1] Japanese Patent Application Publication No. Hei 6-308197
However, in the test apparatus disclosed in Patent Document 1, a power supply voltage is fixedly varied while the test pattern is being executed, and hence the resistance characteristics thereof against a variation in pulse-like power supply voltages cannot be checked. In recent semiconductor devices that can operate with increasingly reduced voltages, the resistance characteristics against a pulse-like noise (impulse noise) is an important issue to both of designers and users of semiconductor devices.